Ovoid pipe rehabilitation

by means of single pipe method with annular space

Wastewater pipes with an ovoid geometry have been in use since the 19th century. The benefits of this special pipe geometry are still appreciated nowadays, although the materials used have evolved from simple rubble masonry to state-of-the-art pipe materials made of thermoplastics.

Local authorities now have to cope with large fluctuations in discharge flow, especially in municipal combined water sewers. A dry-weather discharge that has been reduced by water-saving measures, for example, leads to a reduction in the flows of sanitary sewage, which exacerbates the risk of deposits accumulating in the sewers, especially during the summer months. The ovoid shape brings about an increase in flow velocity at the base of the duct, and hence improves hydraulic discharge with a flushing and self-cleaning effect. If precipitation flows and sanitary sewage flows are high, a correspondingly high drainage capacity is available because the profile becomes wider towards the top.

Long-term rehabilitation of ovoid pipes has thus certainly become one of the special challenges in sewer rehabilitation. Renewal of ovoid pipes in an open-cut trench, however, is not always possible. Nor do localised repair measures ensure permanent solutions for system operators.

In response to this problem SIMONA AG has created a solution with engineering partners from the pipe rehabilitation sector. With SIMONA® PE 100 ovoid pipes – either with push-fit (type: karo-san) or welded – damaged old sewers can be rehabilitated with maximum reliability.

As a system manufacturer, SIMONA offers lining pipes, internal and external saddles and application-specific special fittings according to the requirements of the situation on site – tailored to the method of single pipe lining for ovoid cross sections.